Epitaxial PbTiO3 thin films were prepared in situ by pulsed laser deposition on MgO(001) and SrTiO3(001) single crystal substrates. The effects of oxygen pressure and substrate temperature on the growth of films were investigated. The favorable conditions for the fabrication of epitaxial films were identified. Appropriate control of oxygen pressure in the range of 200-250 mTorr was necessary for epitaxial PbTiO3 thin films and higher substrate temperature up to 700 degrees C was preferred. The epitaxial relation between film and substrate is PbTiO3{001}//MgO(001), PbTiO3[100]//MgO[100]. The chemical composition of the film was very similar to the ideal stoichiometry of PbTiO3.